This invention relates to vehicle door latches and more particularly to door latches that include a deadbolt locking mechanism.
Automobiles conventionally include a door latch on each vehicle door to hold the door in a closed position. Each vehicle door latch includes a lock that is commonly actuated from inside the vehicle by a readily accessible door lock button or other manually operable device on the door. The vehicle door locks for the front doors are also conventionally operated from outside the vehicle using a key lock cylinder.
In addition to manual buttons and key cylinders, it is conventional to employ a power actuated lock system as a feature of the latches. The power lock system generally uses an electrically powered actuator associated with each door latch. The actuator is used to move the door lock between its locked and unlocked position. The electric actuators are typically activated by switches accessible from inside the vehicle and switches on the door lock key cylinder.
One feature of conventional manual and power door lock systems is that they can be actuated from inside the vehicle by a readily accessible manually operable button. As a consequence, although a door is left in a locked condition, access to the inside door lock button permits the unwanted unlocking of a vehicle door latch. Due to this condition unwanted access to the vehicle can occur through a partially open window, a broken window or by circumventing the window to access the door lock button.
To deter unwanted access to vehicles through the means described above, it is known to include a deadbolt locking feature with a vehicle latch. The deadbolt locking feature disables the inside door lock button from unlocking the lock mechanism and therefore, prevents unwanted opening of the doors. When a vehicle is in the deadbolt state all the doors are locked and cannot be unlocked manually using the inside door lock button.
Conventional deadbolt locking systems include a mechanical deadbolt system on the driver door and power systems on the remaining doors. In case of power failure, the mechanical system still works. A problem with this system is that deadbolt can only be engaged/disengaged from one side of the vehicle. For the deadbolt to be engaged/disengaged from either front door or by remote, all doors must have power deadbolt locking systems.